Key and type bar action



Feb. 2, 1932. .1. ALEXANDER KEY AND TYPE BAR ACTION Filed Aug. 19, 1929 2 Sheets-Sheet A TTORNEY.

Feb. 2, 1932. J ALEXANDER 1,843,117

KEY AND TYPE BAR ACTION Filed Aug. 19, 1929' 2 Sheets-Sheet 2 INVENTOR. Jsse A/exaviez;

ATTORNEY.

Patented Feb. 2, 1932 UNITED STATES PATENT ()FFICE JESSE ALEXANDER, OF LOS ANGELES, CALIFORNIA, ASSIGNOR 0F ONE-HALF TO W. W. IPAYNE, OF LOS ANGELES, CALIFORNIA KEY AND TYPE BAR ACTION Application filed August 19, 1929.

This invention is a key and type bar action for a typewriter, and relates particularly to a a key and type bar action which is of extremely simple and durable construction, and which provides a light touch and a quick and positive action assuring smooth and quiet running.

More particularly it is the object of the invention to actuatethe' type bars by suitable levers, with a lost-motion operating connection between each type bar and its actuating lever, and each type bar'provided with shoulders which are respectively in front and rear of its actuating lever, withthe front shoulder adapted for initial engagement by its corresponding actuating lever to start the printing stroke while there is lost-motion at the operating connection, and said operating connection then completing the printing stroke after the lost-motion has been taken up, and the rear shoulder of the type bar then engaging the actuating lever upon completion of the printing stroke so as to start the type bar on its return stroke.

It is a still further object of the invention to provide a lost-motion connection between each key lever and its corresponding actuating or intermediate lever which is operatively connected to the type bar, in order that said lost-motion connection shall cushion the stroke on the key and thus produce an easy action; and this lost-motion connection between a key lever and its corresponding intermediate lever also provides for the momentum of the swinging type bar freely throwing it all the way to printing position without the possibility of the intermediate lever which is connected thereto retarding such accelerated swinging movement, as would result if it were not for said lost-motion connection between the key lever and the intermediate lever premitting movement of the intermediate lever in advance of the key lever re 'sponsive to said accelerated movement of the type bar, and without waiting for the relatively slower movement of the manually shifted key lever.

Serial No. 886,819.

Further objects of the invention will be readily understood from the following description of the accompanying drawings, in which:

Fig. 1 is a vertical section through a typewriter showing one of the keys and its corresponding type bar and intermediate lever, with the parts in normal position of rest.

Fig. 2 is a similar view with the parts in printing position.

Fig. 3 is a horizontal section on the line 3&3 Of 1.

Fig. 1 is a detail view of the intermediate lever and type bar, showing the parts in an intermediate position with the lost-motion of the operating connection taken up so that the operating connection is ready to form a positive drive.

Fig. 5 is a perspective view of the type bar.

Fig. 6 is a perspective view of the intermediate lever.

The respective key and type bar mecha nisms are of similar construction, and for clarity of illustration but one of said mechanisms is shown with its type bar 7 pivoted at 8 in a type bar segment 9. The type bar is provided with front and rear dependent arms, with the forward arm 10 providing a driving means at commencement of the type bar stroke, and the rear arm 11 adapted to start the type bar on its return stroke. To provide ample bearing surface the ends of arms 10 and 11 are preferably angularly disposed so as to form bearing lugs 12 and 13 respectively.

The key lever 15 for type bar 7 is shown pivotally supported on a transverse bearing rod 16 which is journaled for rocking movement in the frame of the typewriter, and the key lever is held in normal raised position by a spring 17 attached to the rear end of lever 15, with the spring preferably adapted for adjustment by means of a screw 18.

An intermediate lever 20 is preferably made separate from the key lever 15 so that a certain amount of lost-motion may be provided. Thus in the present instance the separate intermediate lever 20 is fixed on the pivot rod 16 alongside its key lever and the intermediate lever with the forward lug 12 of the type bar as shown in Fig. 4,

and at completion of the printing stroke the rearward lug'lS of the type bar engages the rear side of the intermediate lever as shown in Fig. 2, so as to initiate the return stroke of the type bar. The forward lug 12 is so spaced from the pivot 8 of the type bar as to provide considerable leverage at starting the printing stroke, and consequentlya relative-- ly light touchis sufficient to initiate movement of the type bar; and as soon as the type bar is thus started on its printing stroke the lost-motion of pin and slot connection 26 is taken up as shown in Fig. 4, so that the pin and slot provides a positive drive in completing the printing stroke as shown in Fig. 2. The slot 25 in which driving pin 26 works, is shown as more or less oval shaped to allow for the compound movements of the intermediate lever and type bar, but the exact shape and relation of the parts may be varied without departing from the scope of the invention.

In operation, when key lever 15 is first depressed it moves idly a v slight distance against the tension of its spring 17 between the spaced lugs 22 of the intermediate lever, 'so as to provide a lost-motion which is finally taken up by the key lever engaging one of.

the lugs 22, and the intermediate lever is then shifted with the key lever duringfurther depression of the key. The inter'medi-I ate lever thus imparts motion to the type bar through theengagement of the forward edge of the intermediate lever with the forward or driving lug 12 ofthe type bar, and during this starting movement the pin 25 moves idly in the slot 26in the type bar until the pin engages the 'far end wall of the slot, whereupon the parts in a position approximating'that shown in Fig. 4, the pin 25 takes hold and carries the type bar positively forward to the end of the printing stroke as shown in Fig. 2, with the momentum of the swinging type bar throwing it forward and carrying its intermediate lever along with it for freely accelerated motion of the type bar, without the necessity of extremely accurately designed-relationship between pin 25and slot 26, since even without such accuracy of design the intermediate lever may V freely swing withthe type bar and without being held back by the slower movement of The type bar is started on its printing stroke by engagement of the forward side of and 33. escapement mechanism compr1s1n a universal bar 40 supported by arms 41 xed to the the manually actuated key lever, due to the lost-motion connection between the key lever and the intermediate lever permitting the intermediate lever being swung by the accelerated type bar in advance of the movement of the .key lever. Approximately at the moment of impact by the type bar against the platen,the rear lug 13 of the type bar engages the rear edge of the intermediate lever and an impulse is thus imparted to the type bar for starting it on its return movement. The otherelements of the typewriter such as the carriage construction and the ribbon feed may be of any suitable construction, with the carriage showngenerally as of the type described andclaimed in my copending application Ser. No. 386,820, ofeven date herewith, and comprising a platen 30 mounted in a carriage 31 which travels on guide rails 32 The carriage may be shifted by anq gg.

rod 16 which is rocked by intermediate lever 20, so that the universal bar is shifted whenever a key lever isdepressed. The universal 5 9o barmay be connected by a link 42 to a rocker 43, with the, rocker-pivoted at 44 and carry- 'ing"pawls 45 cooperating with a rack 46. on the carriage. The tension of the escapement may be regulated by a screw 47 connectedto iezi a spring 48 which engages rocker 43, with the 'scre'w'held in its adjusted position by a lock nut 49. p p

The ribbon feeding and lifting mechanism is illustrated as comprising usual vertical' icl) shafts6O for the ribbon spools,with the shafts 6O fiXed on ratchet wheels 61'which are respectively actuated by pawls 62 to feed the ribbon in opposite directions. The pawls 62 may be-guided in slots 64 in the type bar 5 segment-9, and are preferably fixed to a transverse rod 63 which extends through the rocker 43 above its pivot 44, so that shifting of the rocker responsive to movement of the universal bar 40 will shift the rod 63 in suit- 116 able guideways' found on the frame of the machine, in order to turn one or the other of ratchet wheels 61 by its corresponding pawl. A shaft 66 having manual control knobs 68 is adapted for turning so as to position oneiiia of the pawls 62 for operative engagement --with its ratchet wheel 61 and at the same time retract the other pawl to a position where it willnot operatively engage its ratchet, thereby providing a construction whereby turning 320 of control knobs 68- will reverse the ribbon feed. As an instance of this arrangement the pawls 62 are normally yieldably projected by springs 65'to positions Where they will operatively engage their respective' -iss pawls, and cams 67 on shaft 66 engage the respective pawls and areso arrangedthat turning shaft 66 in one direct-ion willcause one of the cams to retract its corresponding pawl to inoperative position, with the other 13c cam releasing its pawl for spring projection to operative position, while opposite turning of shaft 66 will cause a corresponding reverse positioning of the pawls. The ribbon may be lifted to the printing point by a usual lift guide 86 which is preferably actuated by the link 42, the operating connection being shown as a lever 51 connected at one end to the lift guide and operatively engaged at its opposite end by the link 42 as shown at 50.

The improved key and type bar action is extremely simple and inexpensive but practical for all purposes and provides an action which is of light touch and positive and speedy in its movement.

I claim:

1. In a key and type bar action, a key lever, an intermediate lever alongside the key lever and having a lost-motion connection therewith whereby the key lever is adapted for initial movement without moving its intermediate lever and is then adapted to swing the intermediate lever with said intermediate lever free for accelerated swinging movement without being retarded by the key lever, a

pivoted type bar provided with an arm disposed in front of the intermediate lever for engagement by the forward edge of said intermediate lever upon commencement of the printing stroke, the type bar having a slot therein, a pin on the intermediate lever working in said slot and forming a lost-motion connection adapted to provide a positive drive for accelerating swinging movement of the type bar after commencement of the printing stroke and permitting free swinging of the accelerated type bar to full printing position as a result of the lost motion connection between the intermediate lever and the key lever compensating for any tendency of said positive driving connection to retard said free swinging movement of the type bar, and a rearwardly extending arm on the type bar disposed in rear of the intermediate lever and adapted for engagement by the rear edge of said intermediate lever upon completion of the printing stroke.

2. In a key and type bar action, a key lever, an intermediate bell-crank lever with one arm alongside the key lever having oppositely transversely projecting integral ears at its swinging end bent at right angles to the plane of said arm so as to form vertically spaced lugs disposed one above and one below the key lever so as to provide a lost-motion connection between the key lever and the inter mediate lever, and a pivoted type bar operatively engaged by the intermediate lever.

3. In a key and type bar action, a key lever, an intermediate lever having a lost-motion connection therewith whereby the key lever is adapted for initial movement without moving the intermediate lever and is then adapted 55 to swing the intermediate lever with said intermediate lever free for accelerated swinging movement without being retarded by the key lever, a pivoted type bar, a lost-motlon connection between the intermediate lever and the type bar, and abutments on the type bar, one of which is adapted for engagement by the intermediate lever to initiate the printing stroke and the other of which is adapted to impinge against the intermediate lever upon completion of the printing stroke, the lostmotion connection between the intermediate lever and the type bar providing a positive drive for accelerating swinging movement of the type bar after commencement of the printing stroke and permitting free swinging of the accelerated type bar to full printing position as a result of the lost-motion connection between the intermediate lever and the key lever compensating for any tendency of said positive driving connection to retard said free swinging movement of the type bar.

In testimony whereof I have aflixed my signature.

JESSE ALEXANDER. 

